Lactones have been employed in the prior art to produce alkylsulfonyl acids. However, the processes employed were either difficult to operate or relied upon scarce starting materials. Processes for the convenient production of sulfonyl acids and in particular alkylsulfonylbutric acids, have not been available. .gamma.-butyrolactone has been employed in several different processes whereby the lactone ring is opened and either a sulfide or sulfonyl acid is prepared. In the case of the sulfide, the acid is oxidized to the sulfonyl form.
An example of such use of the lactone ring opening method is found in U.S. Pat. No. 2,603,658 to Hanusch which discloses a reaction of .gamma.-butuyrolactone and the sodium salt of benzene sulfonic acid to prepare the sodium salt of phenylsulfonyl butyric acid. The lactone was disclosed as not only the reactant in the process but also as a solvent when employed in excess. The free acid was obtained by dissolving the reaction product in water and reprecipitating it with mineral acids. While sulfonic acids are known these materials are not generally available.
Thioethers have been produced by ring opening reactions employing lactones with a Lewis acid such as aluminum halide. The thioethers is formed by reacting a thiol with the lactone. Several lactones are reported to have been employed while both alkane and aryl thiol compounds were found to be useful in this process. Such a process is described by Node et al in J.O.C. pp 5163-5166, Vol. 46, (1981). While the thioethers were reported to have been prepared there was no suggestion to further react the thioethers to provide the sulfonyl containing organic acid.
In an entirely different process, lactone ring opening has been described by reactions of mercaptans with lactones in the presence of sodium metal. One example of such a reaction is disclosed by S. S. Kukalenko, Zhur. Organ. Khimii, Vol. 6, No. 4, pp. 682-685 (1970). According to this publication, a mixture of thiophenol, alcohol and either metallic sodium or potassium reacts in the solvent with butyrolactone to provide an aryl thiobutyric acid which was oxidized to a sulfonyl acid. A similar process is also disclosed by Kresze et al Chem. Ber. 94 pp. 2060-2072 (1961). This publication also discloses the reaction of .gamma.-butyrolactone with a thiophenol in methanol and in the presence of sodium. A thioether is produced.
However, processes have been known whereby alkylsulfonyl acids are provided by oxidations of a corresponding acid containing a thioether group. Symmetrical diacids are prepared from butyrolactone and sodium sulfide. Butyrolactone was employed as a reactant and a solvent in the reaction provide the thioether containing acid. The thioether was then oxidized to the sulfone dibutyric acid with an oxidizing agent. For large scale production it was suggested that chlorination in aqueous solution be employed to convert the thioether to the sulfone. Oxidation of the crude thioether reaction product dissolved in water was also disclosed. Of course, by this process only symmetrical diacids could be prepared. A disclosure of such a process is found in Acetylene and Carbon Monoxide Chemistry, pp. 156 and 157.
Other processes for preparing sulfonylacids is described in U.S. Pat. No. 2,969,387 to Horn et al. Severe reaction conditions are required to prepare a di (sulfonylalkanoate). According to this procedure butanedithiol is dissolved in aqueous ethanol containing sodium hydroxide. After the mercaptide is formed, butyrolactone is added slowly at a temperature of from 190-210.degree. C. Heating at this high temperature proceeded for 24 hours. The product was then filtered and dissolved in water and acidified to produce a dithiol dibutyric acid. To form the sulfonyl acid, the dithiol dibutryic acid is dissolved in water containing sodium hydroxide and treated with peracetic acid, while maintaining the pH of the reaction in the range of from 6 to 7 by addition of sodium hydroxide. After addition was completed, the sulfonyl acid was recovered. While this process accomplishes the production of a sulfonyl acid, the reaction conditions are severe and extended. Also, because of the severe conditions, a high boiling solvent such as dibutyl carbitol was employed in the reaction with the lactone and low yields, in the order of 50%, is reported.
Several different approaches to prepare sulfonyl acids is reported by Rapoport et al, JACS 69, 693 and 694 (1947). Three general methods are described to provide alkylmercapto acids which are (1) the condensation of a mercaptan with the appropriate halo-acid, halo-ester, or halo-nitride, followed by hydrolysis where necessary; (2) the alkylation of a .omega.-mercapto acid with an alkyl iodide; and (3) the addition of a mercaptan to acrylonitirile followed by acid hydrolysis of the resultant nitrile. Oxidation of the thioether with hydrogen peroxide provide the alkysulfonyl acid. Severe reaction conditions and long reaction times are reported.
There has recently been discovered novel sulfone mono-peroxy and diperoxy acids exhibiting extra ordinary stability and attractive properties for use as bleach for laundry detergent use. Examples of such sulfone peroxy acids are found in U.S. Pat. Nos. 4,758,369 and 4,824,591. The sulfone peroxy acids have exhibited such unusually favorable properties as bleaches for detergent use in home laundry detergents. Production in large volume to supply such need has not been heretofor available. There is thus needed a convenient, efficient and safe process for preparing sulfonyl acids, the precursors for sulfone peroxy acids.